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  • Küçük Resim
    Öğe
    Facile preparation of sulfonated carbon particles with pomegranate peels as adsorbent for enhanced methylene blue adsorption from aqueous solutions
    (Springer Science and Business Media LLC, 2024-01-19) Yaşar Genel; İlyas Genel; Cafer Saka
    In this study, in the first stage, activated carbon (AC) is produced from pomegranate peels, which are commonly found in Turkey, by pyrolysis after impregnation with NaOH (PPAC). In the second stage, the surface properties of the obtained PPAC sample are further improved by the sulfonation modification process with sulphuric acid (PPAC-S) for selective MB adsorption. For the characterization of the obtained samples, XRD, FTIR, SEM, nitrogen adsorption/desorption and EDS analyses were performed. Additionally, the zero charge points (pHzpc) of these samples were also determined. The isotherm, kinetic, and thermodynamic properties of the MB adsorption process with PPAC-S were examined. The qe values obtained for MB adsorption with PPAC and PPAC-S samples were found to be 98.79 mg/g and 199.18 mg/g, respectively. There is an increase of 100% in MB adsorption with the sulfonated PPAC adsorbent. Maximum adsorption capacity values of MB with the Langmuir model at temperatures of 298, 308, and 318 degrees C were 212.7, 216.9, and 245.1 mg/g, respectively. Additionally, the mechanism of MB adsorption onto PPAC-S was also attempted to be elucidated.
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    Öğe
    Utilisation of Cu2O/CuO@N, O doped catalysts on activated carbon particles derived from biological wastes for highly active hydrogen production with sodium borohydride methanolysis
    (Elsevier BV, 2025-05) Cafer Saka
    Despite the significant advantages of hydrogen (H2) production via sodium borohydride (SB, NaBH4) methanolysis, it is important to further develop this reaction with more efficient and cost-effective catalysts. Here, in the first stage, pomegranate peels, which are widely consumed in the world and Turkey, were evaluated in the production of activated carbon as biowaste (PPAC). In the second stage, the obtained PPAC was hydrothermally treated with nitric acid for O atom doping on the surface (O-doped PAC). In the third stage, Cu2O/CuO and N atoms particles were doped on the O-doped PPAC by hydrothermal method (Cu2O/CuO@N, O-doped PPAC). These Cu2O/CuO@N, O doped PPAC nanoparticles were used for the first time for effective H2 production from NaBH4 methanolysis(SB/ H2P). The active regions obtained based on Cu2O, CuO, N, and O particles on the carbon support exhibited HGR values of 4775 and 40622 mL/min/gcat for PPAC and Cu2O/CuO@N, O-doped PPAC, respectively. A significant increase of approximately eight times was achieved in the hydrogen generation rate (HGR) value. The XPS, EDS, and FTIR analyses successfully confirmed both CuO particles and O, N atoms doping into the PPAC structure. The activation energy for this reaction was 29.45 kJ/mol.
  • Küçük Resim
    Öğe
    Utilisation of green nitrogen-doped biomass-based hierarchical porous activated carbon particles for enhancement of electrochemical energy storage performance
    (Elsevier BV, 2025-02) İlyas Genel; Yavuz Yardım; Cafer Saka
    Activated carbon particles were obtained from rosehip wood-based carbon precursor by chemical activation with potassium hydroxide (RHAC). After this pyrolysis process, nitrogen-doped hierarchical porous carbon was prepared by ammonia activation (N-doped RHAC). The prepared carbonaceous materials were designed as an electrode for a supercapacitor. Standard electrochemical analyses were performed. The specific capacitance (Cs) of RHAC/GCE was determined to be 25 F/g at 2.5 mV/s and 23 F/g at 0.2 A/g. In contrast, the N-doped RHAC/GCE demonstrated significantly higher Cs values of 119 F/g at 2.5 mV/s and 121 F/g at 0.2 A/g. According to CV and GCD measurements, the N-doped RHAC material exhibited approximately a fivefold increase in specific capacitance compared to the RHAC-based electrode. A specific capacitance retention rate of 94.6 % was obtained after 1000 cycles at a current density of 1.6 A/g. The surface properties and characteristics of the obtained materials were carried out by SEM, nitrogen adsorption, Raman, FTIR, EDS and XPS analyses. EDS and XPS analyses showed that N atom doping was successful. This study suggests that rosehip tree biomass-based N atom doped carbon material is suitable for supercapacitors as an electrode.